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9. Phase III Clinical Trials - Development for Launch

Step 9. Phase III Clinical Trials - Development for Launch

Phase III trials (also called confirmatory studies) are the largest, most complicated and most expensive part of the development of a medicine. They aim to confirm the efficacy and safety in a large patient population.

The decision to go on to Phase III trials is only made if it is supported by all the information from earlier studies, manufacturing, and business units. The design of such trials is also critically important. Therefore, there is a large amount of discussion with external experts, Regulatory Authorities, patient groups and others. This ensures that the right questions are being asked and the right information is being collected. The number of patients in the trial is also very important so that the results can be properly interpreted and will meet the requirements of sound scientific rigour.

All of the information gathered from the earlier stages is used to make important decisions including:

  • The final formulation of the medicine (how the active medicine is combined with other chemical substances).
  • The dose to be tested.
  • Which patients can be recruited (inclusion criteria).
  • Which patients cannot be included (exclusion criteria).
  • How many patients are required (sample size).
  • The trial design.
  • The length of the trial.
  • How efficacy and safety will be measured.
  • The statistical tests that will be used.

At this stage, the trials may involve thousands of patients, are often run in many countries, and require extensive expertise to run them effectively. They are therefore time consuming and cost-intensive. However, this is the only way to allow a clear benefit-risk assessment between the efficacy of the medicine (it works) and its safety (it is well tolerated).

Phase III studies make up the largest, most complicated and most expensive part of the medicine development process. Over 50% of the medicines fail in this step. The overall failure rate for the projects from the discovery stage is more than 97%. The revenue from the few medicines that make it to the market, will cover the cost of all the projects, the failures as well as the successes.